Anthelmintic compositions containing substituted styrylpyridinium compounds and method of administering same



United States Patent 3 177,116 ANTHELMINTIC CbMPOSITIONS CONTAIN- ING SUBSTITUTED' STYRYLPYRIDINIUM COMPOUNDS AND METHOD OF ADMINIS- TERING SAME Irwin B. Wood, Hopewell, John A. Pankavich, Hamilton Square, and Ronald E. Bambury, Trenton, N.J., assignors to American Cyanamid Company, New York, N.Y., a corporation of Maine No Drawing. Filed Jan. 26, 1962, Ser. No. 169,084 16 Claims. (Cl. 167-53) 'as the active ingredient styrylpyridinium compounds of the formula: 1

in which R is lower alkyl, R is selected from the group consisting of hydrogen and halogen and X is a pharmacologically acceptable anion. The anions may be, for example, chloride, iodide, bromide, YOSO wherein Y is alkyl, etc.

We have found that our new compositions of matter are highly effective and possess advantages over currently used anthelmintics. For example, the new compositions of this invention are effective against both adult and larval stages of helminths such as hookworm. This is in contrast to the usual anthelmintics which are effective against adult worms but not against larvae.

The new compositions of the present invention are highly effective when administered in low concentrations in feed. This method of administration provides continuous prophylaxis against helminths causing zoonoses in man (i.e. Ancylostoma braziliense, causative agent of cutaneous larval migrans creeping eruption). The majority of currently used anthelmintics indogs are inactive in feed and must be given, in facts, to fasted animals. Among these anthelmintics are toluene, tetrachlorethylene, N-butyl chloride, bephenium, etc. present compositions have a wide therapeutic index or margin of safety which permits their continuous use for maximum protection against helminth infection. The present compositions are stable under processing and storage conditions employed in manufacturing both canned meat type and meal type feed. This is in contrast to the majority of anthelmintic compounds which are unstable or otherwise unsuitable for use in feed.

Another advantage of the compositions of the present invention is their compatability with other anthelmintic feed additives such as diethylcarbamazine. The active components of the present composition in combination with diethylcarbamazine as an anthelmintic feed can provide significant prophylactic control of parasites in animals. Furthermore, the compositions of the present The "'ice invention are palatable to dogs, sheep, swine, rabbits and similar animals. Also, the active components of the compositions of the present invention do not stain feed stuff (feces, animals or environment during any phase of treatment. This is in contrast to some currently used anthelmintics which are intense dyestufis.

The active component of the new compositions can be present in amounts of from 0.25 mg. to mg. of active ingredient for each kg. of animal body weight in an edible carrier depending upon the animal to be treated and the mode of administration. In medicated feed for repeated continuous daily administration the concentration of active ingredient may range from 5 p.p.m. to not more than 2000 p.p.m. of the total feed or correspondingly greater concentration when only a portion of the medicated feed is used in the daily animal rations. The compositions of the present invention may also consist of the active component in combination with various pharmaceutical carriers, for example, non-toxic liquid solvents, gums, cellulose gums, processed proteins such as soy and peanut, various cereals such as wheat germ, rice flour, potato flour, corn and feed stufis per se. Also, in addition to using the present compositions in feed, they can be used in capsules, tablets, oblets, pills and similar forms of medication well-known to those skilled in the art of compounding pharmaceutical preparations.

The compositions of the present invention were tested in animals experimentally infected with known numbers of infective helminth larvae. Puppies and young dogs were inoculated with 200-300 larvae of Ancylostoma caninum or A. braziliense. In tests against larval stages, treatment was started one day after infection and was continued once daily in feed for ten days. More effective control may be obtained, however, by a longer treatment period as shown in Table III. The effectiveness of the anthelmintic was determined by comparsion of the number of worms present in treated and untreated control dogs at necropsy.

Against adult worms of 28 days or more, single oral doses, by capsules, and repeated daily doses in feed for seven days were tested. Efiicacies of treatments were determined on the basis of pretreatment egg count and the number of worms in treated dogs at necropsy. Standard parasitological and microscopical techniques were used to evaluate the effects of the compounds. The efficacy of a single oral dose of salts of 1-methyl-2-(pchlorostyryD-pyridinium compounds against adult A. caninum hookworm in dogs is summarized in the following Table I.

TABLE I The eflicacy 0 single oral doses of salts of I-methyl-Z-(pchlorostyryl)-pyridinium compounds against adult A. caninum hookworms in dogs grarn=adult A. caninum.

doses given once .daily of 1 -niethyl-2- (p-chlorostyryl) pyridinium chloride in feed are summarized below.

i TABLE II The effect of seven doses, given once daily, of I- methyI-Z P (p-chlorostyryl)-pyridinium chloride in feed AN'C'YL OSTOMA CANINUJVI I Number of worms Dose in feed, Aprox. Number Pie-treatment, at necropsy (average) Percent mg./kg body percent Type of feed of dogs eggs/gram 01- effieacy weight diet 1 feces (average) 7 (average) Expected e Actual 2. 5 01 Meal 2 7, 100 142 22 '85 2. 5 .005 Canned meat 6 8, 300 p 166 11. 93

2.5 .005 Canned meat (auto- 2 2,900 58 0- .100

. elaved). V

5 02 M'ea'l 4 8, 200 164 2 99 5 O1 7 Canned meat- 3 3, 500 70 3 i 99 5 01 Canned meet b 4 2, 900 58. 1' j 98 A. BRAZILIENSE 5 .01 Canned meat 2 p 2, 050 0' 100 the effective low doses of the active components of the present inventioneliminate the larvae before they begm B Basedori 50 eggslgram= 1 adult A. ca'm'mtm. b Processed under mfg. conditions.

hoolcworms'is caused by severe anemia resulting from the bloodsucking of the imrn'aure hookworm in the prepatent stages of infection (before positive diagnosis can be made by the presence of'eggs in the feces). The currently used anthelmintics are not effective against the im mature stages but. eliective in the mature adult therefore 'To determine theeliectiveness of the compositionsof the present invention over a longer period of time,.repeated doses of I-methyl-Za(p-chiorostyryl)-pyridinium chloride were administered in feed to dogs with immature and mature Ancylostoma caninuml. Data are summarized below;

TABLE 111 The efiects of repeated doses of l methyl-2-(p-chlorm' V styryD-pyridinium chloride, administeredv in feed, on immature and mature Ancylostoma caninumin dogs a Data from meal and meat-type feeds combined, as nosigm'fieant difierence between feeds was present.

b Treatment begun one clay after inoculation of dogs with A. ca mnimn. Untreated control animals.

. allowing a period-of .one to two weeks of bloodsucking to occur before Worrnscau be eliminated. (Each worm is estimated to suck.0.1 cc. of blood per day.) However;

sucking blood. The medication of thefeed of pets-and livestock with the present compositions is ideally suited 1 for the prophylactic control of helminth infections which inexperinierits carreid out using varioussubstituted: styrylpyridiniurn compositionsit was found that these compositions forming-the-subject matterof the presentin-v f 7 vention are active; whereas others are substantially inac tive. The following Table ,IV'illujstrates the eflicacy of;

the active as Well. as the inactive compounds when com,

- paredto 1-methyl 2-(p-chlorostyryl):pyridinium chloride 7 affect man directly and indirectly The effects of different 75 .as a standard.

g as possible and refluxed for 3 hours.

ai /7,1 1e

V 7 TABLE IV I Comparison of the anthelmintic eflectiveness of the styrylpyridiniwn analogs against hookworms in dogs Active analogs:

Efficacy relative to Substituents l-methy1-2-(p-chlorostyryl)- pyridlnium chloride R X Single oral Repeated dose doses in feed Inactive analogs: v

I No evidence of activity at highest doses tested (generally, 10X minimal efietgivefdose of 1-methy1-2-(p-ehlorostyryl)-pyridinium chloride.

*Emetie at lower doses also. I

The following examples describe in detail the preparation of representative styrylpyridinium compounds found useful in the compositions of the present invention.

EXAMPLE I To 219.3 grams of 1,2-dimethylpyridinium methylsulfate in 750 ml. of isopropyl alcohol is added 140.6 grams of p-chlorobenzaldehyde and 20 ml. of piperidine. The mixture is brought to the reflux tempearture as rapidly The reaction mixture is then evaporated to one-half the original'volume and cooled in an ice bath. The solid is filtered and dried. Further reduction in volume of the mother liquor gives a second crop. Total yield, 213.5 grams of 1-methyl-2- (p-chlorostyryl)-pyridinium methylsulfate, melting point EXAMPLE II To 170 grams of 1-methyl-2-(p-chlorostyryl)-pyridinium methylsulfate is added 350 ml. concentrated hydrochloric acid and the mixture isheated on a steam bath for one hour. To this solution is then added 112.1 grams of barium chloride dissolved in water and the heating is continued for an additional hour. Diatornaceous earth is then added and the mixture is filtered. The solution is evaporated and the solid residue is recrystallized from isopropyl alcohol. Two crops of crystals bring the yield to 228 grams of 1-methyl-2-(p-chlorostyryl)*pyridinium chloride, melting point 220-223 C.

: EXAMPLE 111 To 21.9 grams of 1,2-dimethylpyridinium methylsulfate in 100 ml. of hot isopropyl alcohol is added 18.5 grams of p-bromobenzaldehyde and 5 ml. of piperidine. The mixture is then refluxed for 3 hours. f'lhe mixture isthen evaporated to one-half of its original volume and cooled. The solid which forms is filtered and recrystallized from isopropyl alcohol giving 21.0 grams of 1-methyl-2-(pbromostyryD-pyridinum methylsulfate, melting point 179-180 C. Y

EXAMPLE IV To 12.9 grams of l-methyl-Z-(p-bromostyryD-pyridinium methyl-sulfate isiadded 30nd. concentrated hydrochloric acid and the mixture is heated onthesteam bath for one hour. To. this solution is then added 8. 1 grams of barium chloride dissolved in water and the mixture is heated for an additional hour. To the mixture is added 50 ml. of alcohol, 10 grams of diatomaceous earth and the mixture is then filtered.v The residue is washed withcthanol. The filtrate and washings are combined and evaporated, to dryness. The residue is crystallized from isopropyl alcohoL giving 9.5 grams of l-methyl-Z-(p-bromostyryD-pyridinium chloride, melting point 137139 C. V

7 EXAMPLE V T I To 23.5 grams of 1,2-d-imethylpyridinium iodide in 100 ml. of isopropyl alcohol is added 10.6 grams of benzaldehyde and 2 m1. of piperidine. The mixture is refluxed 3 hours and then evaporated to dryness. The solid remaining is recrystallized from aqueous methanol to give 15.0 grams of 1-methyl-2-styrylpyridinium iodide, melting point 220-221 C.

We claim:

1. A method of controlling helminthiases in warm blooded animals by introducing orally into the animals a helminth-toxic quantity of an anthelmintic composition comprising a compound of. the formula:

wherein R is lower alkyl, R is selected from the group consisting of hydrogen and halogen and X is a pharmacologically acceptable anion, and an edible carrier.

2. The method of claim 1 in which the compound is l-rnethyl-Z- (p-chlorostyryl)-pyridinium chloride.

3. The method of claim 1 in which the compound is I-methyl-Z-(p-chlorostyryl)-pyridinium iodide.

4. The method of claim 1 in which the compound is 1-methyl-2- (p-bromostyryl)-pyridinium methylsulfate.

5. The method of claim 1 in which the compound is 1-methyl-2- (p-bromostyryl)-pyridinium chloride.

6. The method of claim 1 in which the compound is 1-methyl-2-styrylpyridinium iodide.

7. The method of claim '1 in which the compound is 1-methyl-2- (p-chlorostyryl -pyridinium methylsulfate.

8. A method of eradicating helrninths in an animal by introducing orally into said animal an anthelmintic composition comprising a carrier and a helminth-toxic quantity in the range of 5 p.p.m. to 2000 p.p.m. of a compound of the formula:

composition comprising 5 p.p.m..to-2000 p.p.m.-of 1- methyl-Z-(p-chlorostyryl)-pyridiniun1:chloride in animal feed, said: compound being substantially equaliyfdisper sed insaid feed. i 7 a 4 10. An anthelmintie compositien coniprisingia eompoundaof the formula: a

cologicall'y acceptable anion-rand animal feed as a'carrier for said' compound, said anthelmintic component being a 7 present in'from 5 ppm. to 2,000 p.p.m.

11. An'anthelmintic composition comprising 'l-met h yl- 2-(p ch1orostyry1)-pyridinium ehloride, and an animal feedasa carrier, said anthelmintic component being present in from 5 ppm. to 2,000 ppm,

12. An anthelmintic composition comprlsing 1-methy1- 2-(p-chlorostyryl pyridinium'rnethylsulfate and an animal feed as a carrier, said anthelmintie component being present in from 5 p.p.rn/to" 2,000 p.p.m. I 13;. An anthel m intic composition comprising l-methyl I V8 2-(p-brornostyry1) pyridiniumimethylsulfate and an animal feed as a carrier, 'tsaid anthelrnintie component being present in from 5 ppm. to 2,000 p.p.m. 1

14. An anthelmintic' composition' comprising l-methyl- 2-styrylpyridiniun1 iodide andsan animal feed as a car rier, said anthelmintic component being present in from 5 p.p.m. to,2,000 p.p.m; a r

15. An anthelmintic composition comprising l-rnethyl- 2-(o-chlorostyry1)-pyridinium iodide and 'an animal feed as a ;carrier,' said anthelmintic component: being present in'from 5 ppm. to 2,0 00 p.p.m. I

16-. An anthelrnintic composition comprising an animal feed containing-from 5 p.p.m. to 2,000 p.p.rn. of 1- methy1-2- (p-ch1orostyry1)-pyridinium ehloride References Cited by the Examiner- UNITED STATES PATENTS 2,742,463 4/56 Finkelstein- 260-240 OTHER REFERENCES Chemical AbstractSubj'eeLlndeX 'v' lumess, 1959,

page 23565 (col. 2); LEWIS GO S, Primary Examiner.

, MORRIS o. WOLK, FRANK CACCIAPAGLIA; 11k;

Examiners. 

1. A METHOD OF CONTROLLING HELMINTHIASES IN WARM BLOODED ANIMALS BY INTRODUCING ORALLY INTO THE ANIMALS A HELMINTH-TOXIC QUANTITY OF AN ANTHELMINTIC COMPOSITION COMPRISING A COMPOUND OF THE FORMULA: 